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Topic: technical articles by JohnZ (Read 2173 times)

Reminder, for those that do not know , JohnZ has posted a series of wonderful articles pertaining to timing , cooling system ,valve adjustment etc. Written in easy to understand format pertaining to principal/ troubleshooting. I've posted before : great as a refresher or a must read if you are just getting in to theses old cars. Just click on Technical Articles on the home page.

Would help many a poster from running in circles when they are having some issues and are looking for help. Take the time to read over these first , everybody here likes to lend a hand so to speak, and some of the replies just might seem a little clearer. Unfortunately, you just can't stop by with a 12 pack

They really are great - John has contributed soooo much to our hobby. I just read the foundry article & could add just a couple of points of interest from the perspective of the Tonawanda Metal Casting Plant (where I worked for part of my time at GM). The shape of the center screw on the "clock" definitely had significance at Tonawanda. First shift castings had a "flat" center screw, and second shift castings had a "round" head on the screw. Also, the position of the clock pointer indicated the actual hour of the day (not the hour of the shift). Some GM foundries (like CFD) utilized two "clocks" on their patterns - one indicated "D" or "N" for the shift, and the other indicated the time of day.